Yes, AI was heavily involved in building this but its literally impossible to share a set of prompts as it's several hundred sessions over the course of months. Design, messaging, UX all those things are extremely important to me and this is nothing I'd trust an LLM out of the box.
Founder of Franz here. Was surprised to find this on the front page this morning and I'm happy to answer your questions – there might be a slight delay as weekends are family time though.